简述常用的4类抗生素提取方法。
西周的社会形势是（）。 ["族群","国天下","家天下","家族"]
酸价
天然气是一种（）的气体。 ["淡蓝色、无味","无色，有刺激性气味","无色、无味","淡蓝色、有刺激性气味"]
The network setup for this trouble ticket is shown in Figure 3. Trouble Ticket Statement DSW1 and R4 cannot ping R2’s loopback or R2’s s0/0/0/0.12 IPv6 address. Initial troubleshooting showsand R2 is not an OSPFv3 neighbor on R3. Configurationon R2 ipv6 unicast-routing! ipv6 router ospf 6 router-id 2.2.2.2! interface s0/0/0/0.23 ipv6 address 2026：：1：1/122 ConfigurationR3 ipv6 unicast-routing! ipv6 router ospf 6 router-id 3.3.3.3! interface s0/0/0/0.23 ipv6 address 2026：：1：2/122 ipv6 ospf 6 area 0 Figure 3 On Which device is the fault condition located?（） ["DSW1","DSW2","R2","R3"]
发酵液的预处理是要解决什么问题？
